In a typical ink jet recording or printing system, ink droplets are ejected from a nozzle at high speed towards a recording element or medium to produce an image on the medium. The ink droplets, or recording liquid, generally comprise a recording agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier liquid, typically is made up of water, an organic material such as a monohydric alcohol, a polyhydric alcohol or mixtures thereof.
An ink jet recording element typically comprises a support having on at least one surface thereof an ink-receiving or image-recording layer, and includes those intended for reflection viewing, which have an opaque support, and those intended for viewing by transmitted light, which have a transparent support.
While a wide variety of different types of image-recording elements for use with ink jet devices have been proposed heretofore, there are many unsolved problems in the art and many deficiencies in the known products which have severely limited their commercial usefulness. The requirements for an image recording medium or element for ink jet recording are very demanding.
It is well known that in order to achieve and maintain photographic-quality images on such an image-recording element, an ink jet recording element must:
Be readily wetted so there is no puddling, i.e., coalescence of adjacent ink dots, which leads to nonuniform density PA1 Exhibit no image bleeding PA1 Provide maximum printed optical densities PA1 Exhibit the ability to absorb high concentrations of ink and dry quickly to avoid elements blocking together when stacked against subsequent prints or other surfaces PA1 Provide a high level of gloss and avoid differential gloss PA1 Exhibit no discontinuities or defects due to interactions between the support and/or layer(s), such as cracking, repellencies, comb lines and the like PA1 Not allow unabsorbed dyes to aggregate at the free surface causing dye crystallization, which results in bloom or bronzing effects in the imaged areas PA1 Have an optimized image fastness to avoid fade from contact with water or radiation by daylight, tungsten light, or fluorescent light PA1 I) a support of a solvent-absorbing, porous material, and PA1 II) an image-recording layer comprising a vinyl, latex polymer having the following formula: ##STR2## wherein: A is a hydrophilic, vinyl monomer such as hydroxyethylacrylate, hydroxyethylmethacrylate, acrylic acid, methacrylic acid, acrylic acid, vinyl alcohol, acrylamide, methacrylamide or hydroxyethylacrylamide; PA1 B is a hydrophobic, vinyl monomer such as methylacrylate, methylmethacyrlate, butylacrylate, butylmethacrylate, ethylacrylate, ethylmethacrylate, isopropylacrylate, cyclohexylacrylate, norbornylacrylate, vinylacetate, vinylneodeconate or styrene; PA1 C is a cationic monomer such as trimethylammonium ethylacrylate chloride, trimethylammonium ethylacrylate methylsulfate, trimethylammonium methylacrylate chloride, trimethylammonium ethylmethacrylate methylsulfate, methylvinylpyridinium chloride, methylimidazolium iodide or trimethylammonium ethylacrylamide chloride; PA1 x is from about 10 to about 80 mole %; PA1 y is from about 10 to about 80 mole %; and PA1 z is from about 2 to about 20 mole %. PA1 (a) a matrix of polyolefin; PA1 (b) finely-divided, substantially water-insoluble filler particles, preferably of which at least about 50 percent by weight are siliceous particles, the filler particles being distributed throughout the matrix and constituting from about 40 to about 90 percent by weight of the microporous material; and PA1 (c) a network of interconnecting pores communicating substantially throughout the microporous material, the pores constituting from about 35 to about 95 percent by volume of the microporous material.
Coatings are typically applied to paper when gloss and ink holdout (a barrier to colorant) are required. Such coatings are designed to be insoluble in the ink solvents so that the colorants do not penetrate, causing a matte finish. However, such an approach also prevents the printed images from drying readily, as there is no route for solvent from the ink to the paper.
It is desirable to use a porous material in an ink jet recording element due to its liquid-absorbing capability which yields effective drying. This fast dry-time can enhance the printing efficacy, and in many cases, can improve the printing quality by eliminating the bleeding of two adjacent colors in the print.